If fashion refers to styles which are current at any given time, the social networking application industry will be in business for a long, long time.

Inherent in the term social networking tools is the idea that the mode will change more quickly than the culture as a whole. The terms "fashionable" and "unfashionable" are used to describe whether an application is quickly adopted potentially "enhancing" popular modes of interaction.

From Wikipedia: The term fashion is frequently used in a positive sense, as a synonym for glamor, beauty and style. In this sense, fashions are a sort of communal art, through which a culture examines its notions of beauty and goodness.

In this sense, social networking applications are a representation of a larger ethos, with each user a contributing factor within the the greater gestalt. I like how the Wikipedia authors relate the term fashion to the idea of an agreed upon communal art where notions of beauty and propriety are further explored literally, in this case, in a materialistic mode.

Similarly, fashion can denote a sense of trendiness, or of little or passing value -- passe or non-sustainable. Most people do not want to be associated with such a way of being or doing things, thus, like social networking tools themselves, fashions ultimately exist based on our need to explore, refine, represent, and expand our vision and understanding of our selves.

Artwork: My heroine, Maira Kalman.